Sinus venosus ASD (PAPVR)

Anatomy
- The sinus venosus is the smooth, intercaval portion of the right atrium. The right pulmonary veins pass posterior to the sinus venosus portion of the right atrium to reach the left atrium. A sinus venosus defect results in RPV that return variably to the SVC or RA and an interatrial communication resulting from the normal orifice of the right pulmonary vein(s) into the left atrium; left to right atrial shunting occurs through from the pulmonary vein orifice into the right atrium.
- When the proximal (LA orifice of the) pulmonary vein orifice is atretic, the defect is simply PAPVC with the right pulmonary vein(s) draining to the right sided circulation.

Pathophysiology
- A sinus venosus defect (i.e. isolated PAPVC) results in right ventricular volume overload since the RV must pump a full cardiac output to the LA in addition to the volume that anomalously returns to it.

Postoperative considerations

2 patch repair of PAPVC
- A 2 patch repair of a sinus venosus ASD (or PAPVC) includes (1) closing the defect in the wall between the right pulmonary vein(s) and the sinus venosus portion of the right atrium and (2) an anterior patch augmentation of the right atrium to prevent proximal SVC stenosis.
- General rule is ERAS early extubation. Complications are rare, but include sinus node dysfunction (junctional rhythm), SVC obstruction, and post-pericardiotomy syndrome.
- Patients are frequently treated with ‘line’ heparin, early removal of RIJ, and ASA.

Warden repair of PAPVC
- The Warden Procedure is frequently chosen when the anomalously draining RPV returns cephalad on the SVC, making it more likely that a transvenous baffle (see right) would become obstructive.
- The procedure includes ligation of the SVC cephalad to the anomalous vein, and mobilization of the distal SVC with anastamosis to the right atrial appendage. Frequently, the azygous vein is ligated and divided to permit mobilization. The native orifice of the SVC is then baffled through the sinus venosus defect to the left atrium, completing atrial septation.
- General rule is ERAS early extubation. If applicable, remove internal jugular catheter as early as possible, Complications are rare, but include SVC stenosis (usually due to thrombus), and right phrenic nerve injury (due to its proximity as shown).